[Levels of carnitine and homocysteine in plasma of long-term hemodialysis patients with chronic renal failure]

Abstract

Homocysteine and carnitine are the metabolic products of exogenous amino acids. Increased plasma concentration of homocysteine but decreased or normal carnitine concentration are usual findings in haemodialysis patients with chronic renal failure. This study aimed to evaluate the interrelationship (if any) between the above mentioned metabolites in haemodialysis uraemic patients. 44 haemodialyzed patients with chronic renal failure--HD (25 female, 19 male, mean age 47 +/- 12 years) were enrolled into this study. Blood samples for estimation of plasma glucose, cholesterol, triglycerides, albumin, folic acid, vitamin B12, homocysteine (HC), total (TC) and free (FC) carnitine were withdrawn after overnight fasting before subsequent haemodialysis session. In all subjects whole body total fat mass (TFM) and lean mass (TLM) were assessed by dual X-ray absorptiometry (DEXA). Hyperhomocysteinaemia was found in 90.9% patients, while carnitine deficiency in 22.7% of all analysed subjects. Both hyperhomocysteinaemia and carnitine deficiency was found in 18.2% of haemodialysis patients. Folic acid deficiency regardless of prescribed supplementation was observed in 9.5% patients. A significant positive correlation was found between plasma concentration of TC or FC and TLM (tau = 0.332, p < 0.001; tau = 0.298, p < 0.01 respectively). A negative correlation was observed between plasma concentration of folic acid and homocysteine (tau = -0.201, p < 0.05). No significant relationship was noted between homocysteinaemia, total and free plasma carnitine levels and anthropometrical parameters. In conclusion, plasma concentration of homocysteine and carnitine are independent indicators of abnormal amino acid metabolism in uraemic patients.